1930s Stamped Coro Duette Silver Tone Coro Duette Brooch Frame

1930s Silver Tone Coro Duette Brooch Frame In Great Condition. Stamped Coro Duette & Pat. NO. 1798867 On Back.  This vintage brooch frame measures approximately 2 1/2 wide.  This skeleton back held two identical separate dress clips or fur clips together. The owner could slide the clips onto this frame to wear them as one single large brooch, or remove them from the pin to wear them separately on the corners of a neckline, lapel, collar, pocket, or shoes.  The stamp reads PAT. NO. 1798867 on back of frame. This famous utility patent was issued on March 31, 1931, to Oscar Placco (who assigned it to Cohn & Rosenberger, the parent company of Coro). It covers the special framework mechanism that allows the jewelry piece to transform.  Introduced during the 1930s Art Deco era, the complete multi-functional convertible pin sets became highly popular and remain sought-after collector pieces today. Again this is only the frame for the convertible pins.  Please see pics before purchase.  52